Refrigeration systems, such as building air conditioning systems, typically utilize fluorocarbon refrigerants, such as the refrigerants commonly known as 11 and 113. In the operation of many refrigeration systems, purge gas tends to collect in the upper regions of the condenser of the refrigeration system. The purge gas typically includes uncondensed primary refrigerant, a noncondensable component, such as air, and a condensable component, such as water. The condensable and noncondensable components are more likely to be present in refrigeration systems operating at a high vacuum because a high vacuum tends to draw air and moisture from the atmosphere into the refrigeration system.
One way to eliminate the purge gas is to vent it to the atmosphere. This cannot be done because the refrigerant gas is harmful to the environment. In addition, this would increase the cost of operating the refrigeration system because of the loss of refrigerant inherent in the venting process.
In an effort to solve this problem, it is known to feed the purge gas to a purge drum. The purge drum is a condenser in which at least some of the condensable component and the refrigerant component are condensed. The refrigerant component is then returned to the refrigeration system, the condensable component is bled from the purge drum and the noncondensable component is vented to the atmosphere.
In order to permit the purge drum to function as a condenser, it is necessary to supply it with a condensing or cooling medium. In the prior art, this cooling medium has taken the form of primary refrigerant from the primary refrigeration system or chilled water from the primary refrigeration system.
Unfortunately, none of these prior art techniques have condensed the refrigerant component to the extent desired. Consequently, when the noncondensable component is vented to the atmosphere, the uncondensed refrigerant also escapes to the atmosphere. Thus, prior art purge systems have not been as effective as desired in eliminating the environmentally harmful effects of venting the purge gas.